570 GRAMINE.E. (GRASS FAMILY.) 



lindrical (2' -4' long), somewhat interrupted at the base ; glumes short-pointed, 

 rather narrowly keeled, J longer than the ovate hairy flower. — South Carolina, 

 and westward. (I) — Leaves not glaucous, 4' - 10' long. 



47. PASPALUM, L. 



Spikclets spiked or somewhat racemed, apparently 1 -flowered, awnless, bome 

 in 1 - 4 rows on one side of the flattened or triangular jointless rachis. Glumes 

 2, membranaceous, nearly equal. Palese 2, ovate or roundish, coriaceous ; the 

 lower one larger, concave, and partly enclosing the flattened upper one. Sta- 

 mens 3. Grain included in the indurated palese. Such is the apparent structure 

 of the spikelet, but theoretically it is 2-flowered, as in Panicum, with the lower 

 glume and upper palea of the lower flower undeveloped. 



* Spikes racemed: spikelets partly enclosed by the recurved margins of the broadly 



winged membranaceous rachis. 



1. P. fluitans, Kunth. Spikes very numerous ; spikelets in two rows, mi- 

 nute (%" long), oblong, pubescent; glumes pointed; culm branching, ascending 

 from a creeping or floating base; leaves flat, broadly linear (4"- 8" wide). 

 (Cercsia fluitans, Ell.) — River-swamps, Florida, and northward. Sept. and 

 Oct. (j) —Culms smooth, l°-3° long. 



2. P. Walteri, Schultes. Smooth; spikes 3 - 7, the lowest ones included 

 in the sheath of the uppermost leaf; spikelets in two rows, ovate, smooth ; glumes 

 obtuse, 5-nerved. (P. vaginatum, Ell.) — Low cultivated grounds, Florida to 

 North Carolina, and westward. July and Aug. — Culms decumbent, creeping, 

 l°-3°long. Leaves linear, short. 



* * Spikes mostly by pairs, divaricate: spikelets ovate-lanceolate, acute, 1-rowed on 



the slender wingless rachis : glumes smooth, longer than the paleoz. 



3. P. Digitaria, Poir. Peduncles elongated, lateral and terminal, often 

 2-3 together from the upper sheath; spikes (3' -4' long) filiform, spreading 

 horizontally ; glumes even, 7-nerved, J longer than the obtuse perfect flower ; 

 culms ascending from a creeping and branching base ; leaves lanceolate, obtuse, 

 flat, mostly fringed on the margins, the sheaths compressed. (Milium paspa- 

 lodcs, Ell ) — Open swamps, Florida to North Carolina, and westward. July - 

 Sept. U — Culms 1 ° - 2° high. 



4. P. vaginatum, Swartz. Peduncles single, terminal, spikes (rarely 3 or 

 4) short ( 1 ' - 1^' long), erect or horizontal ; glumes rugose, 5-nerved, rather longer 

 than the acute flower; culms diffusely creeping, short-jointed; the flowering 

 branches (4' - 10' long) erect ; leaves ( I' - 3' long) subulate-convolute, their dilated 

 imbricated sheaths persistent. (P. furcatum, Fluegge.) — Saline swamps, West 

 Florida, and southward. Aug. and Sept. }J. — Culms 2° - 4° long. Sheaths 

 compressed, bearded at the throat. 



* * * Spikes solitary, or few and racemose: spikelets ovate or roundish, in 2-4 



rows: rachis mostly flattened andjlexuous: glumes and paleoz nearly equal. 



5. P. distichum, L. Spikes 2, rarely 3 or 4, spreading (l'-l^' long); 

 spikelets in 2 rows, single, ovate, acute, as wide as the straight rachis ; glumes 



